BRPI0916005B1 - spectrometer comprising a filter wheel - Google Patents

Abstract

A spectrometer comprising a filter wheel, a filter wheel and a spectrometer including a filter wheel are disclosed. the filter wheel has a first support structure in which a first plurality of filters are mounted and a second support structure in which at least one filter is provided. A radiation source generates a radiation beam, and a beam splitter divides the radiation beam into a first detection path and a second detection path. The first plurality of filters are selectively mobile in the first detection path. at least one filter of the second support structure is arranged to be arranged in the second detection path. The spectrometer includes a first radiation detector that detects radiation passing through the filter selected in the first detection path, and a second radiation detector that detects radiation passing through the filter in the second detection path.

Description

SPECTROMETER UNDERSTANDING A HISTORIC FILTER WHEEL OF THE INVENTION

The present invention relates to spectrometers and, more particularly, to a filter wheel and a spectrometer using the filter wheel.

DESCRIPTION OF RELATED TECHNIQUE

Gas analyzers such as spectrometers are widely used in medical applications to measure the concentration of carbon dioxide, oxygen gas and anesthetic agents, such as halothane (2-bromo-2-chloro-1,1,1trifluoroethane), enflurane ( ether-2-chloro-1,1,2, trifluoroethyl-difluoromethyl), isoflurane (2-chloro-2 (difluoromethoxy) -1,1,1-trifluorethane), sevoflurane (2,2,2-trifluoro-1- ether [trifluoromethyl] ethylfluoromethyl) and desflurane (ether-2,2,2-trifluoro-1-fluoroethyl-difluoromethyl) during the patient's anesthesia. There are two main types of gas analyzers: the gas analyzers that are located in the main path of a patient's respiratory gases (main flow metering gas analyzers or main flow gas analyzers) or the measuring gas analyzers side flow. Lateral flow analyzers take a sample from a patient's breathing circuit to an adjacent instrument on which the gas analysis is, in fact, performed. On the other hand, main flow or main current measurement analyzers calculate the gas concentration directly in the patient's breathing circuit. The main flow analyzer is usually placed near a patient's mouth or trachea. Main gas flow analyzers or spectrometers incorporate the optical and electronic components of the spectrometer in a housing. As a result, in an environment

Petition 870190076160, of 08/07/2019, p. 5/13

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- ^ 15 * 25 clinical, it is desirable for mainstream gas analyzers to be as compact and lightweight as possible.

Respiratory gases can be analyzed by different methods, including dispersive and non-dispersive spectroscopy. The most common method of gas analysis is based on non-dispersive spectroscopy, in which gases absorb radiation energy (for example, infrared energy) at a specific wavelength for the gas of interest (for example, carbon dioxide). carbon). A beam of light from a light source (for example, an infrared light source) is passed through a patient's respiratory circuit. The beam of light that passes through the respiratory circuit is absorbed in several spectral regions specific to the gas in the patient's respiratory circuit. A set of detectors is — positioned— on the opposite side of the patient's breathing circuit. The detector set includes a detector for measuring light intensity and a low-pass filter. Passa-bandpass filter is positioned in such a way that the ~ beam of light will pass through the filter before reaching the detector. The bandpass filter can be selected to filter out the unwanted regions of the wavelength spectrum in the light beam and transmit a spectral region of interest corresponding to a region of gas absorption in the patient's respiratory circuit.

While conventional mainstream analyzers can work well for a small number of specific, non-overlapping spectrum wavelengths (for example, when analyzing individual gases like carbon dioxide), this type of system has some limitations. For example, conventional mainstream analyzers can become inefficient for analyzing a plurality of gases in which more than 2 or 3 wavelength regions can be involved,

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15-20 requiring the use of one. plurality of_filters.

SUMMARY OF THE INVENTION

One aspect of the present invention is to provide a filter wheel for use in a spectrometer. The filter wheel includes a body with a base and a side wall connected to the base. The body is configured to be rotatable on an axis of rotation. The filter wheel further includes a plurality of radiation filters disposed on the base, and a plurality of radiation filters disposed on the side wall.

Another aspect of the present invention is to provide a spectrometer that includes a filter wheel with a body constituted by a base and a side wall, the body configured to be rotatable on an axis of rotation. A plurality of radiation filters arranged on the base, and a plurality of radiation filters arranged on the side wall. The spectrometer also includes a first radiation detector - arranged to detect the radiation received by the filters arranged in the base, and a second radiation detector arranged to detect the radiation received by the filters arranged in the side wall. The spectrometer also includes at least one radiation beam splitter configured to divide a radiation beam into a first portion of the beam and a second portion of the radiation beam, so that the first portion of the radiation beam is received by the first radiation detector. radiation and the second portion of the radiation beam is received by the second radiation detector.

Another aspect of the present invention is to provide a spectrometer with a radiation source capable of generating a radiation beam, a beam divider that receives the radiation beam and divides the radiation beam into a first detection path and a second detection path , and a filter wheel. The filter wheel has a first structure of

4/30 support on which a first plurality of filters is mounted, and a second support structure on which at least one filter is provided. The first plurality of filters is selectively mobile in the first detection path. At least one filter of the second support structure is arranged to be arranged in the second detection path. O ? The spectrometer further includes a first radiation detector arranged to detect the radiation that passes through the selected filter in the first detection path, and a second radiation detector arranged to detect the radiation that passes through the filter in the second detection path.

Yet another aspect of the present invention is to provide a spectrometer that includes a housing, a rotating body disposed in the housing, an axis mounted on the housing and a plurality of seated decks mounted within the housing, and between which the axis is rotatably clamped . A plurality of filters are arranged on the rotating body. The plurality of filters is ^- structured to transmit the ihterva1os desired radiation wavelength.

------------- These and other objects, functions and characteristics of the present invention, as well as the methods of operation and the functions of the elements related to the structure and combination of parts and manufacturing savings , will become more evident with consideration of the following description and ·. 25 appended claims with reference to the accompanying drawings and which form part of this specification, where similar reference numbers designate corresponding parts of the various FIGS. In one embodiment of the invention, the structural components illustrated here are designed to scale. It should be expressly understood, however, that the drawings are for the purpose of illustration and description, and are not intended to define the limits of the invention. As used in the specification and

5/30 claims, the singular forms one, one, o and a include plural references, unless the context clearly indicates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS. FIG. 1 is a schematic representation of a spectrometer, according to a configuration of the present invention;

FIG. 2 is a schematic front view of a filter wheel, according to a configuration of the present invention;

FIG. 3 is a cross-sectional view of the filter wheel along the cross-section BB, as shown in FIG. 2;

FIGS. 4A, 4B and 4C represent a sequential energization of the stator poles of a motor to rotate the filter wheel 15 in accordance with a configuration of the present invention;

FIG. 5 is a schematic front view of a 'wheel of threads, according to another embodiment of the present' invention; and

20 ..... FIG. 6 is a cross-sectional view of the filter wheel along the cross section BB, as shown in FIG. 5.

DETAILED DESCRIPTION OF THE CONFIGURATIONS OF THE INVENTION

FIG. 1 is a schematic representation of a spectrometer 10, according to a configuration of the present invention. Spectrometer 10 includes a housing 12 with an opening 13, adapted to receive a conduit or airway adapter 14, in order to connect the housing 12 to an airway adapter 14. The airway adapter 14 can be connected to the tubing or other conduit (not shown) that leads to a patient's respiratory tract, such as the patient's mouth or nose. The airway adapter 14 can also be connected to a breathing apparatus (not

6/30 shown), such as a ventilator, to assist a patient's breathing. The housing 12 includes two opposed openings 12A and 12B that communicate directly with respectively two openings covered ^_ ~ of the opposite walls 14A and 14B provided in the airways 5 14. The openings 12A, 12B, 14A and 14B are aligned along the same XX axis. The windows 15A and 15B are mounted on the airways 14 to hermetically seal the side openings 14A and 14B, respectively, on the airway adapter 14, so that the gas in the airways 10 does not escape through the side openings 14A and 14B.

Spectrometer 10 also includes a radiation source 16 for emitting radiation (for example, infrared light), a beam splitter 17, a filter wheel 18, an engine assembly 19, and radiation detectors 20 and 15 " 21. ~ ^_ radiation source 16, the beam splitter 17 ~ ^_ of the filter wheel 18 and the radiation detectors 20:21 may optionally be mounted on a substrate 12. the radiation source 16 may be mounted on one side of the housing 12, such that the light emitted by the radiation source 16 is directed towards the opening * 12A of the housing 12.

Alternatively, the radiation source 16 may not be mounted on a housing 12, and can be supplied separately from the housing, for example, outside of spectrometer 10. In one configuration, an optical fiber, for example, can be used to guide the 25 light from the radiation source 16 towards the opening 12A of the housing 12. The radiation source 16 may include a radiation emitter, such as an infrared emitting diode and a control circuit for controlling the radiation emitter.

The filter wheel 18 is rotatable. In one configuration, the filter wheel can be pivotally mounted on housing 12. Motor assembly 19 is configured to turn filter wheel 18. Divider beam 17 is arranged on the filter wheel next to or in front of opening 12B at

7/30 frame 12, as will be described in more detail in the following paragraphs. The radiation detector 20 is disposed on an opposite side of the housing 12 opposite the filter 18 and ..... in front of the opening 12B in the housing 12 along an X-X axis. 5 The radiation detector 21 is arranged along an YY axis substantially perpendicular to the XX axis and in front of a side wall of the filter wheel 18. The radiation detectors 20 and 21 can be mounted, for example, on a housing 12, or mounted on a cover (not shown) of spectrometer 10. Alternatively, the radiation detector can be provided separate from spectrometer 10, in which case the optical fibers can be used to guide the light coming out of the filter wheel 18 for radiation detectors 20, 21.

The radiation detectors 20 and 21 include a radiation sensor, a polarization and amplification circuit, and a signal processing unit for amplifying and processing an electrical signal output by the radiation sensor. ’In a configuration? a radiation detector 20 is selected to detect in the middle infrared region 20 (mid-IR) of the spectrum (for example, between about 3 pm and about 8 pm), and a radiation detector 21 is selected to detect in the infrared (IR) region of the spectrum (for example, between 7 pm and 15 pm). In one configuration, the radiation detector (mid-IR) 20 comprises a 25 lead selenide (PbSe) sensor. In one configuration, the radiation detector (IR) 21 comprises a pyroelectric sensor. Examples of the type of radiation detector that can be used here are described, for example, in U.S. Patent 7,235,054 to Eckerbom issued June 26, 2007, in U.S. patent

6,486.4 74 to Owen et al. granted on November 6,

2002 and U.S. Patent 5,464,982 to Drucker et al. granted on November 7, 1995, the contents of which are hereby incorporated by reference.

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FIG. 2 is a schematic front view of a filter wheel 18, according to a configuration of the present invention. FIG. 3 is a cross-sectional view of the wheel — of filters 18 along cross-section B-B, as shown in FIG. 2. In one embodiment, the filter wheel 18 has a body 18A with a circular base 24A and an annular side wall * 24B connected to the base 24A. The base 24A and the side wall can be constructed as separate pieces, or they can be integrally formed as a single piece. For example, the base 24A and side wall 24B of the filter wheel can be integrally formed from plastic in an injection molding process. In one configuration, the filter wheel 18 has a cylindrical shape like a drum or a wheel. The filter wheel 18 comprises a plurality of '15 filters 22A and' 'a plurality of filters 22B. The filters 22Á 'are arranged in the openings in the base 24A of the cylindrical filter wheel 18 (drum rim). The filters 22A are arranged in the "" 'openings in the side wall 24B of the filter wheel 18 cylindrical (drum rim).

In one embodiment, the filters 22A arranged in the base 24A are azimuthally spaced at the same angle around the axis of rotation of the filter wheel 18. In one configuration, filters 22B are spaced evenly around the side wall 24B. In an alternative configuration, filters 22A may be spaced azimuthally at different angles and / or filters 22B may be spaced the same distance or different distances.

Filters 22A can have the same size and / or shape, or different sizes and / or shapes. Likewise, filters 22B can have the same size and / or shape, or different sizes and / or shapes. In one configuration, one or more filters (for example, filter 22A or filter 22B) can be of a size or shape to expand and occupy the position of two or

9/30 plus -filters (for example, filters 22A or filters 22B). Such an arrangement eliminates signal interruption and signal loss caused by the opaque filter wheel body. In this case, the light can be transmitted through the expanded filter 5 for a period of time two, three or more times the time of other filters (filters 22A or filters 22B) on the filter wheel 18, thus providing , a longer signal integration time, which can improve the signal-to-noise ratio for the expanded filter.

In an exemplary configuration, 4 (four) filters

22A are provided on the base 24A of the filter wheel 18, and 10 (ten) filters 22B are provided on the side wall 24B of the filter wheel. However, as can be appreciated, any number of filters 22A can be provided on the base 24A, and ““ 15 any number of filters 22B can be provided on the side wall or rim 24B of the filter wheel 18. Although the filter wheel 18 described here in a cylindrical shape and with a generally circular base, other shapes are also within the scope of the present invention. For example, the filter wheel 20 18 can be cylindrical in shape with a polygonal shaped base (for example, triangular, square, hexagonal, octagonal, decagonal, etc.). For example, in the case of a cylindrical shape with a decagonal base, each of the 10 filters 22B can be positioned on each rim of the 10 side walls v 25 of the cylinder with a decagonal base.

In one configuration, two 22A filters are selected to transmit in the middle infrared (mid-IR) region of the spectrum, in the carbon dioxide absorption spectrum (C0 ₂ ). In one configuration, the transmission spectral region of the two C0 ₂ 22A filters is selected between about 3.5 pm and about 5 pm. A narrow spectral range can also be used, if desired, as a narrow spectral range centered at about 4.25 pm for C0 ₂ filters

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22A. Another 22A filter can be selected for transmission in a spectral range centered around 4.56 pm on the nitrous oxide absorption spectrum (N ₂ O). Another 22A filter can still be selected for transmission in a spectral range centered at about 3.69 pm on the absorption spectrum of a reference substance. In one configuration, the reference substance can be a calibrated quantity of C0 ₂ .

In one embodiment, filters 22B on the side wall 24B of wheel 18 can be used to transmit various wavelengths in the absorption spectrum of various chemical agents, such as, but not limited to, anesthetic agents (eg, halothane, enflurane, isoflurane , sevoflurane and desflurane) or other medications. In a —15 configuration, ΊΌ (ten) filters 22B-are provided on the side wall 24B of the filter wheel 18. Each 22B bandpass filter can be selected for transmission in a specific absorption spectral region for one or more agents chemicals. Alternatively, one or more filters 22B can be identical to each other and transmit the same spectral region. The absorption peaks of various chemical agents of interest are in the wavelength range between about 7 pm and about 15 pm. The most intense absorption peaks occur between 7 pm and 10.2 pm. In one configuration, the 5 (five) t 25 chemical agents of interest, such as halothane, enflurane, isoflurane, sevoflurane and desflurane, for example, have about 9 (nine) absorption peaks between about 7 pm and about 10 , 2 pm. There are several possible combinations of filters that can be implemented. A possible selection of filters can be a series of bandpass filters with a wavelength transmission centered around 9.65 pm, 9.10 pm, 8.60 pm, 8.20 pm and 8.00 pm. If measurement of more chemical agents is required, more bandpass filters can be

11/30 added or replaced as desired.

Although the filters 22A positioned at the base 24A of the filter wheel 18 are described above as filters that transmit in mid-IR (for example, between about 3 pm and about 8 pm) and the filters 22B arranged on the side wall 24B of the filter wheel 18 being described above as filters that transmit in the IR range (for example, between about 7 pm and about 15 pm), it can be appreciated that the filters of 22A and 22B can be switched. For example, the 10 filters 22A that transmit in mid-IR (for example, between about 3 pm and about 8 pm) can be positioned on the side wall 24B of the filter wheel 18, while the filters that transmit in IR (for example, example, between about 7 pm and about 15 pm), they can be positioned on the base 24A of the filter wheel 15. In addition, they are Another 'configuration', for example, filters that transmit visible light can be arranged in the filter wheel base 24A 18, while filters that transmit in the mid-IR and / or other IR variations may be arranged in the side wall 24B of the filter wheel.

In one configuration, the filter wheel 18 can be pivotally mounted on the housing 12 by means of a support structure 26. In one configuration, the support structure 26 is a cup and ball type system, and comprises two curved cups 27 and an elongated shaft 28 with 25 two rounded or semi-spherical terminations 28A and 28B. The elongated shaft 28 is pivotally secured between the two seated cups 27. Specifically, the rounded spherical ends 28A and 28B of the elongated shaft 28 are brought into contact with the concave surface of the two seated cups

27. The seated cups 27 can be mounted on a housing

12, and a cover (not shown) of spectrometer 10 and elongated θίχο 28 can be mounted on the filter wheel 18 to define an axis of rotation of the filter wheel. For example,

12/30 in one configuration, the base 24A of the filter wheel 18 can be mounted on the elongated shaft 28, while the side wall 24B, which is connected to the base 24A, may or may not be connected to the shaft 28.

The support structure 26 can provide a low friction rotation system. In addition, the support structure

- 26 can provide the self-centering of the filter wheel 18.

In addition, the filter wheel 18 can tolerate shock, since the shaft 28 will tend to align with the seated cups 27.

Although a cup and ball type system is illustrated here, it can be appreciated that other types of support systems can be used, such as magnetic supports or supports of rolling elements or ball supports, etc.

- - ₁₅ —- - Although ^- the rcda'de · filters 18, including the base 24A and * the side wall 24B, are described here as being pivotally mounted on the housing 12 by means of the support structure 26, it could be appreciated that, in another configuration, the base 24A can be pivotally mounted on a support structure 26 (for example, mounted on an axis 28), while the side wall 24B can be mounted independently on another structure (for example, fixedly mounted on another structure or pivotally mounted on another structure) or the side wall 24B can be omitted.

4. The filter wheel 18 comprises an armature portion 18B. Armature portion 18B is mounted on the periphery 'of body 18A of filter wheel 18. Motor 19 is used to rotate filter wheel 18. In one configuration, motor 19 is a stepper motor like a three-phase motor reluctance 30 variable modified. The motor 19 comprises a rotor portion 30 and a stator portion 32. The rotor portion 30 is part of the armature portion 18B of the filter wheel 18. The rotor portion 30 is configured to interact with the portion

13/30 of stator 32 of the motor 19, to rotate the filter wheel .18 on an axis defined by the axis 28. The rotor portion 30 comprises a plurality of teeth or projections 34. The plurality of teeth 'or projections 34 acts as poles of the 5 rotor.

In one configuration, teeth 34 may be made of a magnetic or magnetizable material, such as soft iron, or a material comprising soft iron, such as silicon steel. The plurality of teeth or projections 34 in the rotor portion 30 10 acts as protruding magnetic poles through magnetic reluctance, and magnetically interacts with a stator portion 32 of the motor 19. The stator portion 32 comprises a plurality of stator coils or poles stator 32A, 32B and 32C spaced around the rotor portion 30. in the configuration 15, the coils ^- the stator 32A, 32B and 32C include electrical stator windings 33A, 33B and 33C for energizing the stator coils 32A , 32B and 32C, respectively. In the "3 (three) Tiled" configuration ^- stator coils or stator poles 32A, 32B and 32C are used. At the

However, it can be appreciated that 2 (two) or more stator poles can be used.

When a rotor pole, that is, a tooth or projection 34 in the rotor portion 30, is equidistant to two adjacent stator poles or stator coils 32A and 32B, i. 25 for example, the rotor pole 34 is in a completely misaligned position. In this position, the maximum magnetic reluctance is reached for the rotor pole 34. When two or more rotor poles 34 are aligned, that is, facing two or more stator poles, the minimum magnetic reluctance

0 is reached. When a stator pole (for example, stator pole 32A) is energized, a rotor torque is developed in the direction that will reduce magnetic reluctance. As a result, the nearest rotor pole 34 is pulled from the

14/30 misaligned position for alignment with stator pole 32A (a position of minimum reluctance).

In order to maintain continuous rotation, the stator coils or poles 32A, 32B and 32C (in the case of an engine comprising 3 stator coils) are arranged so that when one of the stator poles (for example, the pole of stator 32A) is in front of or in alignment with rotor poles 34, the other two stator poles (for example, stator poles 32B and 32C) are not in front or partially in front, that is, they are in misalignment with the rotor poles 34. Thus, as illustrated in FIGS. 4A, 4B and 4C, when the stator poles 32A, 32B and 32C are energized sequentially in a 3-phase electrical configuration, the rotor poles 34 will align sequentially

15 'with ““ the stator poles energized -32A, -32B and- 32CEspecifically, when the stator pole 32A is energized in a first phase, as illustrated in FIG. 4A with hatched linesT the rotor projections or “poles” 34 ^_ of the rotor portion 30 align with the stator pole 3 2A, while other rotor poles 34 on the rotor portion 30 are misaligned with the stator poles 32B and 32C. When the stator pole 32B is energized in a second phase, as illustrated in FIG. 4B with hatched lines, the projections or rotor poles 34 of the rotor portion 30 align with the pole. 25 of stator 32B, while other rotor poles 34 in the rotor portion 30 are misaligned with the stator poles 32A and 32C, thereby forcing the movement of the rotor portion 30 counterclockwise. When the stator pole 32C is energized in a third phase, as illustrated in FIG. 4C with hatched lines, the projections or rotor poles 34 of the rotor portion 30 align with the stator pole 32C, while other rotor poles 34 on the rotor portion 30 are misaligned with the stator poles 32B and 32C, forcing,

15/30 thus, even more the movement of the rotor portion, 30 counterclockwise. By energizing the stator poles 32A, 32B, 32C sequentially, the rotor poles 34 of the rotor portion 30 (and thus the filter wheel 18) will rotate counterclockwise, as indicated by the arrows in FIGS. 4A, 4B and 4C.

In one configuration, motor 19 is configured (for example, the electronic motor controller is configured) in order to keep detector (s) 20 and / or 21 synchronized in 10 series with the rotation of the filter wheel 18. In one configuration, engine 19 does not provide an indication of the rotation of the filter wheel relative to a reference point (for example, the engine does not provide a start reference indication or filter one). Thus, in a configuration, in order '15 'to provide a' reference point for - synchronizing the detector (s) 20 and / or 21 with the rotation of the filter wheel 18, the location of the positions of one of the filters 22A and / or one of the 2ZB filters can be isolated In this way, ^- a zero-detector signal detected by detector 20 and / or 21 when the 20 position of the isolated filter is in the light path, together with the pulses of motor unit 19 and the connected signal sequence for the various phases of motor 19, you can define the location of the filter wheel 18, that is, the location of each filter on the filter wheel 18. In addition to ·. 25 provide synchronization between the rotation of the filter wheel 18 and detectors 20 and 21, the isolated position can also be used to provide a signal shift test for detectors 20 and 21.

In an alternative configuration, instead of or in addition to the use of an isolated filter position, a small magnet can be placed on one of several teeth 34, so that an opposing electromagnetic force (back-EMF) can be generated in a specific 32A, 32B or 32C stator pole, a

16/30 time that the magnet moves beyond the stator. Alternatively, the magnet can also be placed with the poles perpendicular to a plane of the armature portion 18B of the filter wheel 18, anywhere in the armature portion 18B, and a separate pickup coil above or below the magnet can be used to detect when the magnet passes during the rotation of the armature portion 18B (i.e., during the rotation of the filter wheel 18).

In yet another alternative configuration, a small 10 hole can be drilled in the base 24A of the filter wheel 18 ,, in the side wall 24B of the filter wheel 18 or in the armature 18B of the filter wheel 18 (within the radius of the tooth), for that a conventional light emitting diode (LED) can be used to direct the light through the hole to a separate additional photodetector 15 ', so that it receives the light and thus provides a reference point. In essence, any device capable of providing a reference signal (reference point) can be used. "- - _.

Although the filter wheel 18 is shown rotating 20 counterclockwise, a clockwise rotation can also be achieved by energizing the stator poles 32A, 32B and 32C in reverse order, that is, energizing the stator 32C in phase 1, stator pole 32B in phase 2 and stator pole 32C in phase 3. Furthermore, although motor 19 is described here in operation in a three-phase configuration, the motor can also be selected to operate in a two-phase configuration. In the two-phase configuration, there is no inherent start direction. Thus, the teeth 34 can be molded or shading bars added to the armature portion 18B of the filter wheel 18A to define the starting direction. Alternatively, logic can be added to the detector circuit to determine which direction the filter wheel is turning.

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In operation, a beam of radiation 100 emitted by the radiation source 16 is directed towards the opening 12A of the housing 12 to be transmitted through the window in the opening 14A on the airway adapter 14. The radiation beam 100 that passed through window 15A at opening 14A passes through a central portion 15 of the airway adapter 14, then through window 15B at opening 14B, to exit through opening 12B in housing 12. Windows 15A and 15B in the openings 14A and 14B are selected from a material, so that they are substantially transparent at the wavelengths of the radiation of interest (for example, between about 3 pm and about 15 pm) in the radiation emitted by the source of radiation 16. A spectral portion of the radiation beam 100 is absorbed by the molecules (eg CO ₂ ,

15-. N ₂ O ,. or-other chemical substances, or any combination of two or more of them) that are present in the airway adapter 14.

= - _; - the radiation beam 100 - which leaves the opening 12B is divided into two radiation beams 101 and 102 by the beam divider 17 disposed within the filter wheel 18. In one configuration, the beam divider 17 divides the radiation beam 100 in two beams 101 and 102 in two spectral regions, without any substantial energy loss. In another configuration, the beam splitter 17 divides the radiation beam 100 into two beam portions 101 and 102 (for example, with approximately equal intensities), without dividing the beam spectrum 100 into two spectral regions. In this example, a conventional semi-reflective mirror or relatively inexpensive semitransparent mirror can be used as a beam splitter 17 in the radiation of interest. The beam of radiation 101 is directed along axis XX in the direction of one of the filters 22A disposed in the base 24A of the filter wheel 18, and the beam of radiation 102 is directed along the axis

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YY perpendicular to the XX axis in the direction of one of the filters 22B disposed on the side wall 24B of the filter wheel 18. The radiation beam 101 passes through one of the filters 22A on the filter wheel 18 before reaching the radiation detectors 20. The beam radiation 102 passes through one of the filters 22B on the filter wheel 18 before reaching the radiation detectors 21.

Filter 22A filters a portion of a wavelength spectrum from the radiation beam 101 and transmits a portion of the wavelength spectrum centered around a wavelength region of interest (for example, an absorption spectrum region CO ₂ or N ₂ O). Likewise, filter 22B filters out a portion of a wavelength spectrum from the radiation beam 102 and transmits a portion of the wavelength spectrum centered around ~ an IregiacT of “wavelength of interest” For example, a region of the absorption spectrum of a chemical agent such as halothane). Thus, the geometry of the filter wheel 18 coupled with the use of a spectral ~ beam ~ divider allows the use of 2 (two) separate detectors 20 and 21 for the detection of two spectral regions, each detector being dedicated to detecting a spectral region (for example, mid-IR and IR). By rotating the filter wheel 18, a desired filter 22A on the filter wheel can be selected to transmit a desired portion of the wavelength spectrum (e.g., a region of the CO ₂ absorption spectrum) in the radiation beam 101. Likewise, by turning the filter wheel 18, a desired filter 22B on the filter wheel can be selected to transmit a desired portion of the wavelength spectrum (for example, a region of the halothane absorption spectrum) in the beam. radiation 102.

In an alternative configuration, the filter wheel can be constructed in such a way that the base 24A of the filter wheel

19/30 filters ^- be swiveling, while the side wall 24B of the filter wheel is fixed. Alternatively, the filter wheel 18 can also be constructed in such a way that the side wall 24B of the filter wheel is rotatable, while the base 24A of the filter wheel is fixed. In this way, the base 24A or side wall 24B of the filter wheel 18 can be rotated independently of each other, if desired.

In one configuration, beam splitter 17 is mounted on a movable assembly (not shown). The mobile assembly 10 can be a motorized or mechanical mobile assembly. The movable assembly allows the beam splitter 17 to be moved out of the path of the radiation beam 100. When the beam splitter 17 is moved out of the path of the radiation beam 100, the radiation beam will not be divided into ^ T5 two '' beams 101 'and 102. In this case,' the beam 'of radiation 100 continues on its path along the XX axis towards one of the filters 22A disposed in the base 24A of the filter wheel before reaching the detector of radiation 20 in the same manner as described in US Patent No. 7,235,054 to Eckerbom, the entire content of which is incorporated herein by reference.

In the event that two 22A filters are selected to transmit in the medium-infrared (mid-IR) region of the carbon dioxide (CO ₂ ) absorption spectrum, a. CO ₂ absorption is measured, in principle, twice with one revolution. 25 complete, that is, 360 degree rotation of the filter wheel 18. The CO ₂ absorption is measured at each 180 degree rotation of the filter wheel 18. On the other hand, if each of the 10 (ten) filters 22B is selected to transmit in the IR region of the absorption spectrum for a specific chemical agent (eg .30 halothane), the absorption of the specific chemical agent is measured, in principle, once. every turn, that is, 360 degree rotation of the filter wheel 18. If each of the filters 22B is used to measure the absorption of each of the

20/30 chemical agents, the filter wheel is rotated by a step of .. 36 degrees, that is, 360 degrees divided by the number of filters 22B (that is, 10). Thus, an amount of energy collected by CO ₂ molecules in an airway adapter 14 is equal to 5 (180 degree rotation for each CO ₂ filter 22A divided by 36 degree rotation for each agent filter 22B) times amount of energy collected by a chemical agent. As a result, the signal-to-noise ratio for measuring CO ₂ absorption is better than the signal-to-noise ratio for measuring the absorption of chemical agents, the other parameters being the same. In general, the relationship between the amount of energy collected by the CO ₂ molecules and the amount of energy collected by the chemical agent is equal to m / n, where m is the number of agent filters 22B and n is the number of filters 22A for the molecule of interest (for example, ~ CO ₂ ) ~. For example, in the case of N ₂ 0, in which only a 22A filter is used, the relationship between the amount of energy collected by the N ₂ O molecules and the amount of ~ energy? collected by a chemical agent is equal to 10, in principle.

In one configuration, the filter wheel can be configured to rotate at a speed of rotation between about 2 0 00 RPM and about 3 0 00 RPM. For example, a rotation speed of about 3000 RPM provides a sampling rate to measure the CO ₂ absorption of about 50 samples / second. In general, a CO ₂ sampling rate can be between about 50 samples / second and about 100 samples / second, so that a patient's breathing response time can be at least 10 cycles / second, since the average breathing rate for most healthy people ranges from 10 to 18 breaths per minute. If two or more CO ₂ 22A filters are used, the rotation speed can be reduced, for example, divided by 2, to a value between about 1000

21/30

RPM and about 1500 RPM. The response time for other chemical products or agents can be one cycle / second or less, allowing a much slower sample rate than ------ the C0 ₂ sample rate.

FIG. 5 is a schematic front view of a filter wheel 48, according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of the filter wheel 48 along the cross-section BB shown in FIG. 5. Filter wheel 48 is similar in many respects to filter wheel 18. Filter wheel 48 is cylindrical in shape like a drum or wheel. The filter wheel 48 comprises a plurality of filters 52A and a plurality of filters 52B. The filters 52A are arranged in the openings in the base 54A of the filter wheel 48 cylindrical (drum rim). The 15 52B filters are arranged in the side wall openings54B of the cylindrical filter wheel 48 (drum rim). In one configuration, the filters 52A arranged in the base 54A are azimuthally spaced at the same angle around the rotation axis of the filter wheel 48. In one configuration, the 20 filters 52B are equidistantly spaced around the side wall 54B. In an alternative configuration, the 52A filters can be azimuthally spaced at different angles and / or the 52B filters can be spaced the same distance or different distances.

52A filters can have the same size and / or shape, or different sizes and / or shapes. Likewise, 52B filters can have the same size and / or shape, or different sizes and / or shapes. In one configuration, one or more filters (for example, the 52A filter or the 52B filter) can have a size or shape to expand and occupy the position of two or more filters (for example, the 52A filters or the 52B filters) Such an arrangement eliminates signal interruption and signal loss caused by the opaque filter wheel body. In this

22/30. In this case, light can be transmitted through the expanded filter for a period of time two, three or more times the time of other filters (filters 52A or filters 52B) on filter wheel 48, thus providing a longer signal integration time, which can improve the signal-to-noise ratio for the expanded filter.

Similar to the configuration shown in FIG.

2, 4 (four) filters 52A are provided on the base 54A of the filter wheel 48, and a plurality of filters 52B are provided on the side wall 54B of the filter wheel 48. However, as can be appreciated, any number of filters 52A can be provided on the base 54A, and any number of filters 52B can be provided on the side wall or rim 54B of the filter wheel 48. However, in this configuration, the rim or side wall 54B of the filter wheel 48 is more "wide" than the side wall 24B of the filter wheel 18, and thus a greater number of filters 52B can be positioned thereon. For example, as shown in FIG. 6, three rows of 10 (ten) filters 52B can be provided on the side wall 54B of the filter wheel 48. The filters 52B in each row on the side wall 54 can be aligned with each other or positioned in a staggered configuration. The stepped configuration can be used, for example, to reduce the width of the sidewall 54B.

Although the filter wheel 48 is described here in a cylindrical shape and with a generally circular base, other shapes are also within the scope of the present invention. For example, the filter wheel 48 can be cylindrical in shape with a polygonal shaped base (for example, triangular, square, hexagonal, octagonal, decagonal, etc.). For example, in the case of a cylindrical shape with a decagonal base, each of the 10 (ten) 52B filters can be positioned on each of the 10 (ten) side walls of the

23/30 cylinder with a decagonal base for each of the three rows of side wall 54B.

Similar to the configuration illustrated in FIG.

2, two 52A filters can be selected to transmit in the mid-infrared (mid-IR) region of the spectrum, in the carbon dioxide (CO ₂ ) absorption spectrum. Another 52A filter can be selected for transmission in a spectral range centered at about 4.56 pm on the nitrous oxide absorption spectrum (N ₂ 0). Another 52A filter can still be selected for transmission in a spectral range centered at about 3.6 9 pm on the absorption spectrum of a reference substance. In one configuration, the reference substance can be a calibrated amount of CO ₂ .

In one configuration, filters 52B on the side wall 15B 54B of the wheel 4 "can be used ^- to transmit various wavelength regions in the absorption spectrum of various chemical agents, such as, among others, various anesthetic agents or chemical agents ~ and medications. ”The absorption peaks of various chemical agents of interest are in the wavelength range between about 7 pm and about 15 pm. In one configuration, three rows of 10 52B filters are provided on the side wall 54B of the filter wheel 48. Each bandpass filter 52B can be selected for transmission in an absorption spectral region 25 specific for one or more of the chemical agents.

Alternatively, one or more 52B filters can be identical to each other and transmit the same spectral region.

Although the filters 52A positioned at the base 54A of the filter wheel 48 are described above as filters that transmit in mid-IR (for example, between about 3 pm and about 8 pm) and the filters 52B arranged on the side wall 54B of the filter wheel are described above as filters that transmit in the IR range (for example, between

24/30 about 7 pm and about 15 pm)., It can be appreciated that the 52A and 52B filters can be switched. For example, filters 52A that transmit in mid-IR (for example, between about 3 pm and about 8 pm) can be positioned on the side wall 54B of filter wheel 18, while filters 52B that transmit in IR (for example, example, between about 7 pm and * about 15 pm), they can be positioned on the base 24A of the filter wheel. In addition, in another configuration, for example, filters that transmit visible light can be arranged on the filter wheel base 54A 48, while filters that transmit in the mid-IR and / or other IR variations can be arranged on the side wall 54B of the filter wheel.

Similar to the filter wheel 18, the filter wheel 48 is pivotally mounted on the housing 12 by means of

15 'a' support 'structure 2 6. In this configuration, the support structure 26 can be dimensioned to accommodate the larger side wall 54B of the filter wheel 48. For example, the axis 28 of the suppository structure 26 can be longer to accommodate the width of the sidewall 54B of the filter wheel

48. Similar to the configuration illustrated in FIG. 2, motor 19 is used to rotate filter wheel 48, as described in the paragraphs above.

Instead of providing a beam splitter 17 on the filter wheel 18, a plurality of beam splitters 47A, 47B and. 25 47C can be positioned. within filter wheel 48. For example, beam splitter 47A can be positioned on filter wheel 48 so as to direct a portion of the radiation beam towards a filter wheel 52B in a third row of side wall 54B . The beam splitter 30 47B can be positioned on the filter wheel 48 so as to direct a portion of the radiation beam towards a filter wheel 52B in a second row of the side wall 54B. The 47C beam splitter can be positioned on the

25/30 filters 48, in order to direct a portion of the radiation beam towards a filter wheel 52B in a first row of the side wall 54B. Likewise, instead of providing a radiation detector 21 disposed in front 5 of the side wall of the filter wheel 48, as illustrated in FIGS. 2 and 3, a plurality of radiation detectors 21A, 21B and 21C can be arranged in front of each row of side wall 54B of filter wheel 48. For example, radiation detector 21C can be positioned facing 10 the first row of sidewall 54B near base 54A, radiation detector 21B can be positioned facing the second row (center row) of sidewall 54B, and radiation detector 21A can be positioned facing the third row of wall side 54B, 15 as shown in FIG; 6.

In one configuration, each of the beam splitters 47A, 47B and 47C divides an incident radiation beam into two beams in two "spectral 7" regions without any substantial energy loss. In another configuration, each of the 20 beam splitters 47A, 47B and 47C divides the incident radiation beam into two beam portions (for example, with approximately equal intensities), without dividing the spectrum of the incident beam into two spectral regions. In this example, a conventional semi-reflective mirror or relatively inexpensive semitransparent 25 can be used as a beam splitter 47A, 47B and 47C in the radiation of interest.

In operation, when the filter wheel 48 is arranged on the spectrometer 10 shown in FIG. 1, in the same way as the filter wheel 18, the radiation beam 100 emitted by the radiation source 30 is directed towards the opening 12A of the housing 12 to be transmitted through the window 15A at the opening 14A in the airway adapter 14 The radiation beam 100 that passed through the window at opening 14A passes through

26/30 a central portion 15 of the airway adapter • 14, then through window 15B in the opening

14B, to exit through opening 12B in housing 12.

Windows 15Ά and 15B have openings

14A and 14B are selected from a material, so that they are substantially transparent at the wavelengths of the radiation of interest (for example, between about 3 pm and about 15 pm) in the radiation emitted by the source

16. A spectral portion of the radiation beam 100 by the molecules (for example, CO ₂ , N ₂ O, or other radiation is absorbed by chemicals, or any combination of two or more of them) that are present in the airway adapter 14 radiation 10 0 coming out of aperture 12B is divided into

The beam of two radiation beams 100A and 100B through the beam splitter disposed within filter wheel 48O is directed (for example, in a

7 The beam of radiation oriented direction of one of the _: plane of FIG. 6) in the direction located in the third row on the side wall of filters 48 before reaching the detector 21A of the third row of the side wall 54B. The lOOAr beam for filters

Front B

52B wheel for radiation

100B is directed towards the divider 47B arranged on the filter wheel

48. The 100B radiation beam is divided by the 47B beam splitter into two 100C and 100D radiation beams.

The 100C radiation filters beam is directed towards

52B located in the second row on the wall of one of the side

54B before reaching the detector 21B facing the second radiation 100D is row in the side wall 54B. The beam directed towards the beam splitter

47C arranged on the filter divider wheel 48. The 100D radiation beam is divided by the 47C beam into two radiation beams 100E and 100F.

The beam 100E radiation filters is directed towards one of the 52B located in the first row of the side wall

54B before reaching detector 21C facing the

27/30 third row on the side wall 54B. The radiation detector 100F passes through one of the filters 52A before reaching the detector 20 facing the base 54A of the filter wheel 48.

Each filter 52A at the base 54A of the filter wheel 48 and each filter 52B in each row on the side wall 54B of the filter wheel can be selected to transmit a wavelength region of the specific spectrum for an absorption region of the compound. For example, two filters 52A at the base 54A of the filter wheel 48 can be selected to transmit a portion of the wavelength spectrum centered around a wavelength region of interest in the CO2 absorption spectrum. Likewise, filter 22B can be selected to transmit a portion of the wavelength spectrum centered around a 15 _ wavelength region of interest (for example / a region of the absorption spectrum of a chemical agent such as halothane). By providing a plurality of wall filters - side -52B - and the 2ΙΑ, 21B and “2IC” detectors associated with each row of filters 52B on the side wall 54B, absorption in a plurality of wavelength regions can be measured simultaneously. In addition, several rows (for example, the first and second rows) can be assigned to the same general spectral region, in order to measure the spectral details of the spectral region. Alternatively, several rows (for example, the first and second rows) can be assigned to identical spectral regions, in order to provide better statistics of measurement results.

In one embodiment, the filter wheel 48 can be constructed in such a way that the base 54A of the filter wheel is rotatable, while the side wall 54B of the filter wheel is fixed. Alternatively, the filter wheel 48 can also be constructed in such a way that the side wall 54B of the

28/30 filter wheel 48 is rotatable, while the base 54A of the filter wheel is fixed. In this way, the base 54A and the side wall 54B of the filter wheel 48 can be rotated independently of each other, if desired. In yet another „5 configuration, the side wall 54B and the base 54A are rotatable, but independently rotatable from each other.

* Such a provision provides greater flexibility.

In one configuration, the plurality of beam splitters 47A, 47B and 47C can be mounted in one or more 10 movable assemblies (not shown). One or more mobile assemblies can be motorized or mechanically mobile. One or more selected movable mounts allow the selected beam splitters 47A, 47B and / or 47C to be moved out of the path of the radiation beam 100. When the splitters ^- beam 15 4'7A ',' 4 7B and / or 47C'is moved out of the way - of the radiation beam 100, the radiation beam 100 will not be divided into two beams by the beam splitters 47A, 47B and / or 47C. For example, when the '7 ^- beam splitters 4A, 4 7B' ~ and 4 7C are moved out of the path of the radiation beam

100, the radiation beam 100 continues on its path along the X-X axis towards one of the filters 52A arranged in the base 54A of the filter wheel 48 before reaching the radiation detector 20.

When the selected beam splitters, for example, beam splitters 47A and 47B are moved out of the path of the radiation beam 100 while beam splitter * 7C is not moved out of the path of the radiation beam 100, the radiation beam 100 is divided into two beams by the beam splitter 47C. A portion of the radiation beam 100 is directed towards one of the filters 52B located in the first row on the side wall 54B before reaching detector 21C facing the third row on the side wall 54B, and another portion of the radiation beam

29/30 passes through one of the filters 52A located at the base 5.4A before reaching the detector 20 facing the base 54A of the filter wheel 48. As a result, the radiation beam can be directed and divided as desired by the proper positioning of the beam splitters in front of the radiation beam 100.

Although the invention has been described in detail for purposes of illustration based on what is currently considered the most practical and preferred configurations, it should be understood that such detail is exclusively for that purpose, and that the invention is not limited to the disclosed configurations, but, on the contrary, it is intended to cover modifications and equivalent provisions that are within the spirit and scope of the appended claims. For example, it is necessary to understand that the present invention contemplates that, as far as possible, one or more characteristics of any configuration can be combined with one or more characteristics of-any other configuration:

Although the spectrometer and filter wheel of the present invention are described here as being usable for the purpose of measuring compounds or gases in a patient's respiratory tract, it can be appreciated that the spectrometer and / or the filter wheel can be used in other medical applications, such as for measuring chemicals (eg, glucose) in the bloodstream, or used in other non-medical applications, such as measuring concentrations of liquids (eg, liquids and / or gases) in an environment industrial, or the measurement of fluids (eg gases) in environmental applications.

It must be appreciated that, in one configuration, the drawings here are scaled (for example, in the correct proportion). However, it can also be appreciated that other proportions of the parties can be used in other

30/30 settings. *. .

In addition, since numerous modifications and changes will take place quickly with those skilled in the art, one does not want to limit the invention to the exact construction and operation described herein. Thus, all suitable and equivalent modifications must be considered to be within the spirit and scope of the invention.

Claims (11)

(1) a body (18A) with a base (24A) and a side wall (24B) connected to the base (24A), the body (18A) configured to be rotatable about an axis of rotation; 1. SPECTROMETER (10) UNDERSTANDING A FILTER WHEEL (18), characterized by comprising: 2/4 characterized by the plurality of radiation filters (22A) arranged in the base (24A) being selected to transmit in a region of the middle infrared spectrum, in a region of the infrared spectrum, or in a region of the visible spectrum. 2. SPECTROMETER, according to claim 1, Petition 870190076160, of 08/07/2019, p. 6/13 (2) a plurality of radiation filters (22A) arranged on the base (24A), arranged to transmit radiation to a first radiation detector; and 3/4 be mounted on the spectrometer through a support structure (26), where the support structure (26) comprises two seated cups (27) and an elongated shaft (28) mounted on the filter wheel (18), the elongated shaft (28) swiveled between the two seated cups (27). 3. SPECTROMETER, according to claim 2, characterized by the region of the medium infrared spectrum including one selected from the group consisting of (i) wavelengths between about 3 pm and about 8 pm and (ii) wavelengths between about 3.5 pm and approximately 5 pm. (3) a plurality of radiation filters (22B) arranged on the side wall (24B), arranged to transmit radiation to a second radiation detector, in which the first radiation detector is arranged along an axis that connects the first detector radiation with the base of the filter wheel (18), which is perpendicular to an axis that connects the second radiation detector with the side wall (24B) of the filter wheel (18); 4/4 4. SPECTROMETER, according to claim 1, characterized by the plurality of radiation filters (22A) arranged at the base including a filter selected to transmit around a CO2 absorption band, a filter selected to transmit around a peak of absorption of N ₂ O, or a filter selected to transmit around an absorption band of a reference substrate, or a combination of two or more of them. (4) at least one radiation beam splitter (17); and a first radiation detector (20) arranged to detect the radiation received by the filters arranged in the base (24A); and a second radiation detector (21) arranged to detect the radiation received by the filters arranged on the side wall (24B); wherein the at least one radiation beam splitter (17) is configured to divide a radiation beam (100) into a first radiation beam portion and a second radiation beam portion, so that the first beam portion radiation is received by the first radiation detector and the second portion of the radiation beam is received by the second radiation detector. 5. SPECTROMETER, according to claim 1, characterized by the plurality of radiation filters (22B) arranged on the side wall (24B) being selected to transmit in a region of the infrared spectrum, in a region of the medium infrared spectrum, or in a region of the visible spectrum. 6. SPECTROMETER, according to claim 5, characterized in that the region of the infrared spectrum includes one selected from the group consisting of (i) wavelengths between about 7 pm and about 15 pm and (ii) wavelengths between around 7 pm and approximately 10.5 pm. 7. SPECTROMETER, according to claim 1, characterized by the filter wheel (18) being configured to Petition 870190076160, of 08/07/2019, p. 7/13 8. SPECTROMETER according to claim 1, further comprising a portion of the armature (18B), characterized in that the portion of the armature (18B) is mounted on a periphery of the body (18A), where the portion of the armature (18B) comprises a rotor portion (30) with a plurality of projections (34), where the rotor portion (30) is part of a motor (19) configured to rotate the filter wheel (18), and where the rotor portion (30 ) is configured to interact with a stator portion (32) of the motor (19) to rotate the filter wheel (18). 9. SPECTROMETER according to claim 1, comprising: a radiation source (16) configured to emit a radiation beam (100), and a housing (12), characterized by the filter wheel (18), the radiation source (16), and the first and second radiation detectors radiation are mounted on the housing (12). 10. SPECTROMETER, according to claim 9, characterized by the housing (12) being configured to be mounted in the airways (14) connected to a patient's mouth to collect the patient's breath samples, where the airways (14 ) include a plurality of openings (12A, 12B, 14A, 14B), the openings (12A, 12B, 14A, 14B) being covered by the windows (15A, 15B) to substantially seal the openings (14A, 14B), and where the windows (15A, 15B) are selected to be substantially transparent at wavelengths between about 3 µm and about 15 µm of the radiation beam (100). Petition 870190076160, of 08/07/2019, p. 8/13 SPECTROMETER, according to claim 1, characterized in that the at least one radiation beam divider (17) is movable out of the path of the radiation beam (100).